9. ELECTRICITY
growth in renewables and natural gas generation, which are replacing coal as the dominant energy source (and increasingly, ageing nuclear generation as well).
There is currently an active debate and testing of different solutions regarding electric reliability and resilience, including on changes to market designs for wholesale power markets to respond to future trends, at the federal, regional, state and local levels.
Figure 9.1 Electricity generation by source, 2018
|
2% 3% |
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|
6% |
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Natural gas |
7% |
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34% |
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Coal |
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Nuclear |
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19% |
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Hydro |
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Wind |
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Solar
Others*
29%
IEA (2019). All rights reserved.
Coal, natural gas and nuclear accounted for over 80% of total electricity generation in 2018, but the share of renewable energy is increasing.
*Others includes oil products, geothermal and other non-specified generation. Source: IEA (2019a), World Energy Balances 2019, www.iea.org/statistics/.
Electricity supply and demand
Electricity generation and trade
The total volume of US power generation has been stable at around 4 300 terawatthours (TWh) over the last decade. In 2018, the United States generated 4 413 TWh of electricity, which is 2% higher than in 2008. However, the fuel mix of US power generation has gone through a considerable transition. Coal power, which used to cover half of total electricity generation, has declined in the last decade to 28% of the power mix in 2018. One of the main drivers for this development has been the shale gas boom, which has made natural gas-fired generators more cost-competitive than coal power plants. Natural gas-fired electricity production increased by 66% in ten years, and now exceeds coal’s share in the power mix (34% for natural gas in 2018 compared with 28% for coal).
Another development is the growth of renewable electricity, driven by reduced investment costs and policy support. Wind power production increased from 55 TWh in 2008 to 277 TWh in 2018, and is on track to overtake hydro as the largest renewable power source in 2019. Solar power is also growing rapidly, but from a much lower base. In 2018, solar power accounted for 2% of total generation, but production has increased fivefold in the last five years. While wind and solar power are expanding, hydropower remains relatively stable at around 250 TWh to 300 TWh per year.
The remaining share of power generation is mainly from nuclear power, which accounted for 19% of total generation in 2018. Nuclear has been the most stable power source over
182
IEA. All rights reserved.
9. ELECTRICITY
the last decade, with annual outputs varying from 801 TWh (in 2012) to 841 TWh (in 2018). However, in some power markets, nuclear is challenged by cheap gas power and new renewable sources, and struggles to remain cost-competitive (see further in Chapter 10, “Nuclear”).
Figure 9.2 Electricity supply by source, 1973-2018
5 000 |
TWh |
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Oil |
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Natural gas |
4 000 |
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Coal |
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Nuclear |
3 000 |
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Bioenergy and waste |
2 000 |
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Hydro |
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Wind |
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1 000 |
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Solar |
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Geothermal* |
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0 |
1973 |
1978 |
1983 |
1988 |
1993 |
1998 |
2003 |
2008 |
2013 |
2018 |
|
IEA (2019). All rights reserved.
Total power generation has been stable around 4 300 TWh over the last decade, but there has been a significant fuel shift from coal to natural gas and wind power.
*Not visible on this scale.
Source: IEA (2019a), World Energy Balances 2019, www.iea.org/statistics/.
The ongoing energy transition is clearly visible when looking at installed capacity (Table 9.1). Coal power plant retirements have experienced declining installed capacity, falling from around 320 gigawatts (GW) in 2011 to around 260 GW in 2017. Meanwhile, the natural gas power fleet has increased substantially and accounts for the largest installed capacity in the country, with over 40% of the total. Increased installed wind and solar capacity is also remarkable, from a few gigawatts in 2000 to over 130 GW in 2017. Nuclear and hydro capacities remain stable at around 100 GW each.
Table 9.1 Installed electricity generating capacity, 2000-17 (GW)
|
2000 |
2005 |
2010 |
2015 |
2016 |
2017 |
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Nuclear |
97.9 |
100.0 |
101.2 |
98.7 |
99.6 |
99.6 |
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Hydro |
97.6 |
98.9 |
101.0 |
102.2 |
102.7 |
102.7 |
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Wind |
2.4 |
8.7 |
39.1 |
72.6 |
81.3 |
87.6 |
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Solar |
0.6 |
0.9 |
3.4 |
23.4 |
34.7 |
43.1 |
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Geothermal |
2.8 |
2.3 |
2.4 |
2.5 |
2.5 |
2.5 |
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Other sources |
0.0 |
0.5 |
0.3 |
1.3 |
1.3 |
2.0 |
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Combustible fuels |
610.1 |
767.3 |
793.6 |
771.7 |
764.8 |
762.8 |
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Coal |
321.1 |
315.4 |
319.0 |
281.5 |
269.1 |
258.9 |
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Natural gas |
95.8 |
383.1 |
407.0 |
439.4 |
446.8 |
456.0 |
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Other combustion |
45.8 |
68.8 |
67.6 |
50.8 |
48.9 |
47.8 |
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Total capacity |
811.3 |
978.5 |
1 041.0 |
1 072.5 |
1 086.8 |
1 100.3 |
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||||
Source: IEA (2019b), Electricity Information 2019, www.iea.org/statistics/. |
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183 |
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ENERGY SECURITY
IEA. All rights reserved.
9. ELECTRICITY
In 2017, low-carbon electricity from renewables and nuclear accounted for 37% of total generation in the United States. In comparison with other International Energy Agency (IEA) member countries, this share was in the lower half, with a median of 50% lowcarbon electricity (Figure 9.3).
US power systems are interconnected with Canada in the north and Mexico in the south. Most traded electricity consists of imports from Canada, mainly from the hydropower-rich Quebec region, which feeds into northeastern US power markets. Net imports peaked in 2015 at 67 TWh, and have since fallen slightly (Figure 9.4). In 2017, net imports were 56 TWh, equal to 1.3% of total domestic generation.
Figure 9.3 Electricity generation by source in IEA, 2018
Poland
Estonia*
Australia
Mexico
Netherlands
Korea
Japan
Greece
Turkey
Ireland
UnitedUnitedStatesStates
Italy
Czech Republic
Germany
Portugal
United Kingdom
Spain
Hungary
Belgium
Denmark
Austria
Luxembourg
Finland
Canada
Slovak Republic
New Zealand
France
Norway
Sweden
Switzerland
0% |
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20% |
40% |
60% |
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80% |
100% |
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Oil |
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Natural gas |
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Coal |
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Peat |
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Nuclear |
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Biofuels and waste |
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Hydro |
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Wind |
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Solar** |
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Geothermal |
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|||||||||||
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|||||||||||
IEA (2019). All rights reserved.
With 64% fossil fuels in electricity generation, the United States is close to average in the IEA.
*Estonia’s coal represents oil shale.
**Includes solar photovoltaic (PV), solar thermal, wave and ocean power, and other power generation (e.g. from fuel cells).
Source: IEA (2019a), World Energy Balances 2019, www.iea.org/statistics/.
184
IEA. All rights reserved.
9. ELECTRICITY
Figure 9.4 Electricity net imports and exports by country, 2000-17
80 |
TWh |
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70 |
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20 |
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-10 |
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2000 |
2001 |
2002 |
2003 |
2004 |
2005 |
2006 |
2007 |
2008 |
2009 |
2010 |
2011 |
2012 |
2013 |
2014 |
2015 |
2016 |
2017 |
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IEA (2019). All rights reserved.
US electricity imports are mostly from hydropower in Canada.
Source: IEA (2019b), Electricity Information 2019, www.iea.org/statistics/.
Electricity consumption
Total electricity consumption has been relatively stable at just below 4 000 TWh per year over the last decade. The only exception was a decline in 2009, in the aftermath of the financial crisis, which led to reduced energy demand in industry. The residential and commercial sectors dominate electricity consumption, with 76% of total demand in 2017. Residential electricity consumption per capita was 4.2 megawatt-hours (MWh) in 2017, the fourth-highest in the IEA (after Norway, Canada and Sweden).
Figure 9.5 Electricity consumption (TFC) by consuming sector, 1973-2017
4 500 |
TWh |
4 000 |
Transport |
|
|
3 500 |
Industry |
3 000 |
Energy* |
2 500 |
Residential |
|
2 000 |
Commercial** |
|
1 500 |
||
|
1 000
500
0 |
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1973 |
1977 |
1981 |
1985 |
1989 |
1993 |
1997 |
2001 |
2005 |
2009 |
2013 |
2017 |
IEA (2019). All rights reserved.
The residential and commercial sectors dominate electricity consumption.
*Energy includes petroleum refineries, coal mines, oil and gas extraction, coke ovens, and blast furnaces. **Commercial includes commercial and public services, agriculture, and forestry.
Note: TFC = total final consumption.
Source: IEA (2019a), World Energy Balances 2019, www.iea.org/statistics/.
The United States is a large country with several different climate zones, which is reflected in seasonal variations in electricity consumption. Electricity is used for both
185
ENERGY SECURITY
IEA. All rights reserved.